US citizens have not been able to register foreign made automatic weapons since the late summer or early fall of 1968. The registry closed on American conversions of foreign made semi-automatic weapons on May 19, 1986. Of course that is the same date that the registry closed for all automatic weapons for all non-SOTs.

I would be surprised if any companies aside from HK own any of these weapons. Individuals cannot own this weapon. It can only be owned by a business through an SOT.